This invention relates to a one-piece dead-front electrical plug connector, and more particularly to a one-piece dead-front electrical plug connector of high strength which is inexpensive to manufacture and extremely safe in use.
Electrical plug connectors fall into two broad categories, which are electrical plug connectors of the live-front type and electrical plug connectors of the dead-front type. In the live-front type, access to terminal screws for securing wire conductors to the blades of the plug is provided through the face or front of the electrical plug connector. The front of the electrical plug connector is usually covered by a removable insulating disc after the wire connections have been made. The live-front type of electrical plug connectors is characterized by few parts, and accordingly is simple and inexpensive to produce. However, a high level of care in wiring and maintenance is required to provide safe and trouble-free service. In particular, the insulating disc utilized to cover the front of the electrical plug connector and thereby shield the exposed terminal screws and connected wire conductors often becomes loose or is lost from the electrical plug connector.
In electrical plug connectors of the dead-front type, the blades extend through a heavy insulating face or front of the plug, and access to the terminal screws is provided behind the front of the plug. The wiring area, in which wire conductors of a cord are secured to the terminal screws is usually fully enclosed by a cover after wiring is accomplished. Electrical plug connectors of the dead-front type can accommodate greater variations in the quality of wiring and maintenance without loss of safety or service. However, electrical plug connectors of the dead-front type generally comprise more parts and are more costly to produce than electrical plug connectors of the live-front type. Therefore, they have not come into the wide-spread use and acceptance which the greater safety factor associated therewith would seem to dictate.